Hey scotty my 2002 jeep liberty doesn't blow out very much heat it just turned over 100,000 miles we drove it from ca. to Pa. last year here they have inspections it passed with no issues and we are looking for a second car used I just got your book on kindle about buying a used car looking forward in reading it oh by the way it has full antifreeze so its not that ???
Is the engine reaching operating temperature? Might be the thermostat is stuck open and engine not heating up enough.
I don't think those Jeeps have a shutoff valve for the heater core (the later Jeep Cherokees didn't) but if it does have one that may not be operating correctly.
Another thing to check, with the engine warmed up both heater core hoses should be near the same temperature. If one is noticeably cooler you have a blockage. Reverse-flushing the heater core with a garden hose can frequently fix that problem.
Also check that the temperature blend door is operating properly. If it isn't allowing enough hot air into the cabin you'll still get lousy or no heat even if everything else is working OK.
